This invention relates to a process for the production of elemental sulfur from SO.sub.2.
A number of processes are available for converting SO.sub.2 into elemental sulfur. Most are based on two fundamental methods: the reduction of SO.sub.2 over incandescent coke, or the reduction of gaseous SO.sub.2 by reducing gases in the presence of a catalyst. Reference is invited, for example, to BEAVON TGT or SCOT, wherein BEAVON describes the hydrogenation of all S-compounds, with a subsequent Stretford wash of H.sub.2 S, and SCOT describes the hydrogenation of all S-compounds, with a subsquent Amin wash of H.sub.2 S (Hydrocarbon Processing April 1973 p. 87 ff).
Such conventional processes, however, exhibit one or more disadvantages when utilized for the desulfuration of flue gas. During reduction over incandescent coke, many by-products are formed, e.g., COS and CS.sub.2, which must be decomposed in a combustion chamber, and the resultant combustion gas must be recycled to upstream of the flue gas desulfuration. In case of reduction by the addition of a reducing gas (e.g., Hydrocarbon Processing, April 1984, P. 83), a Claus plant of relatively simple design is required to react the H.sub.2 S produced by reduction with SO.sub.2 in order to produce sulfur; however, the investment cost for even such a simple Claus plant is considerable.